Accurate measurement of absolute experimental inelastic mean free paths and EELS differential cross-sections

EELS at very high energy losses

“…For three of these materials (Zr, ZrO 2 and MoO 2 ), these are the absolute numbers from a calculation of: where N , the areal density of atoms in the area exposed to the beam, is calculated from nt , where n is the number of atoms per unit volume (based on detailed knowledge of the crystal structure) and t is the sample thickness. This is obtained from the low loss using a calculated value of the mean free path for inelastic scattering, λ [ 11 , 12 ]. The Mo sample was a sputtered nanocrystalline film – if it is assumed to have the structure of bulk bcc Mo, then this would have a density of 10.22 g cm −3 .…”

“… The effects of oxidation on second row transition metal L-edges: (a) Zr ( t/λ = 0.33, 100 s acquisition) and ZrO 2 ( t/λ = 0.51, 100 s acquisition); (b) Mo ( t/λ = 0.47, 40 s acquisition) and MoO 2 ( t/λ = 0.24, 60 s acquisition); (c) definitions of how the L 3 and L 2 intensities are calculated. Please note, that the vertical scale of (a) and (b) are in units of absolute differential cross section, as previously used in Craven et al [ 12 ] and calculated in a similar way. …”

Role of Convergence and Collection Angles in the Excitation of Long- and Short-Wavelength Phonons with Vibrational Electron Energy-Loss Spectroscopy

“…The inelastic mean free path, λ , for valence shell inelastic scattering from h-BN was computed to be 75 nm at 60 kV (Iakoubovskii et al, 2008). This value of λ is likely to be overestimated by ~25% (Egerton, 1981; Craven et al, 2016; Shinotsuka et al, 2019), and a more reasonable inelastic mean free path would be ~60 nm. Measurements were performed on nanoparticles of different thickness and the results in the figures come from a nanoparticle of approximately 40 nm thickness ( t / λ value ~0.68).…”

Strain effects in core–shell PtCo nanoparticles: a comparison of experimental observations and computational modelling

“…19 For pure Pt nanoparticles, full 3D geometries can be derived from the ADF-STEM images, 20 but it is difficult to do this for alloys without the use of spectroscopic signals such as electron energy loss spectroscopy (EELS) and energy dispersive X-ray spectroscopy (EDX). 19,21,22 An alternative approach to the single image ADF STEM structure determination is to use tomography as shown by some cases in the literature. [23][24][25][26] Tomography is ideal for large nanoparticles where electron beam damage does not affect the morphology of the sample as it is exposed to the electron beam.…”